fix: properly suspend and resume k8s CronJob objects when executing scheduler-cron-write

plugins/scheduler-k3s/Makefile

@@ -1,5 +1,5 @@
 SUBCOMMANDS = subcommands/annotations:set subcommands/autoscaling-auth:set subcommands/autoscaling-auth:report subcommands/cluster-add subcommands/cluster-list subcommands/cluster-remove subcommands/ensure-charts subcommands/initialize subcommands/labels:set subcommands/report subcommands/set subcommands/show-kubeconfig subcommands/uninstall
-TRIGGERS = triggers/core-post-deploy triggers/core-post-extract triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-create triggers/post-delete triggers/report triggers/scheduler-app-status triggers/scheduler-deploy triggers/scheduler-enter triggers/scheduler-is-deployed triggers/scheduler-logs triggers/scheduler-proxy-config triggers/scheduler-proxy-logs triggers/scheduler-post-delete triggers/scheduler-run triggers/scheduler-run-list triggers/scheduler-stop
+TRIGGERS = triggers/core-post-deploy triggers/core-post-extract triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-create triggers/post-delete triggers/report triggers/scheduler-app-status triggers/scheduler-deploy triggers/scheduler-enter triggers/scheduler-is-deployed triggers/scheduler-logs triggers/scheduler-proxy-config triggers/scheduler-proxy-logs triggers/scheduler-post-delete triggers/scheduler-run triggers/scheduler-run-list triggers/scheduler-stop triggers/scheduler-cron-write
 BUILD = commands subcommands triggers
 PLUGIN_NAME = scheduler-k3s
 

plugins/scheduler-k3s/k8s.go

@@ -805,6 +805,35 @@ func (k KubernetesClient) ListTriggerAuthentications(ctx context.Context, input
 	return triggerAuthentications, nil
 }
 
+// ResumeCronJobsInput contains all the information needed to resume a Kubernetes cron job
+type ResumeCronJobsInput struct {
+	// LabelSelector is the Kubernetes label selector
+	LabelSelector string
+
+	// Namespace is the Kubernetes namespace
+	Namespace string
+}
+
+// ResumeCronJobs resumes a Kubernetes cron job
+func (k KubernetesClient) ResumeCronJobs(ctx context.Context, input ResumeCronJobsInput) error {
+	cronJobs, err := k.Client.BatchV1().CronJobs(input.Namespace).List(ctx, metav1.ListOptions{
+		LabelSelector: input.LabelSelector,
+	})
+	if err != nil {
+		return err
+	}
+
+	for _, cronJob := range cronJobs.Items {
+		cronJob.Spec.Suspend = ptr.To(false)
+		_, err := k.Client.BatchV1().CronJobs(input.Namespace).Update(ctx, &cronJob, metav1.UpdateOptions{})
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // ScaleDeploymentInput contains all the information needed to scale a Kubernetes deployment
 type ScaleDeploymentInput struct {
 	// Name is the Kubernetes deployment name

plugins/scheduler-k3s/src/triggers/triggers.go

@@ -123,6 +123,10 @@ func main() {
 		scheduler := flag.Arg(0)
 		appName := flag.Arg(1)
 		err = scheduler_k3s.TriggerSchedulerStop(scheduler, appName)
+	case "scheduler-cron-write":
+		scheduler := flag.Arg(0)
+		appName := flag.Arg(1)
+		err = scheduler_k3s.TriggerSchedulerCronWrite(scheduler, appName)
 	case "scheduler-post-delete":
 		scheduler := flag.Arg(0)
 		appName := flag.Arg(1)

plugins/scheduler-k3s/triggers.go

@@ -163,6 +163,64 @@ func TriggerSchedulerAppStatus(scheduler string, appName string) error {
 	return nil
 }
 
+// TriggerSchedulerCronWrite writes out cron entries for a given application
+func TriggerSchedulerCronWrite(scheduler string, appName string) error {
+	if scheduler != "k3s" {
+		return nil
+	}
+
+	allCronEntries, err := cron.FetchCronEntries(cron.FetchCronEntriesInput{AppName: appName})
+	if err != nil {
+		return fmt.Errorf("Error fetching cron entries: %w", err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, os.Interrupt, syscall.SIGHUP,
+		syscall.SIGINT,
+		syscall.SIGQUIT,
+		syscall.SIGTERM)
+	go func() {
+		<-signals
+		common.LogWarn(fmt.Sprintf("Deployment of %s has been cancelled", appName))
+		cancel()
+	}()
+
+	namespace := getComputedNamespace(appName)
+
+	clientset, err := NewKubernetesClient()
+	if err != nil {
+		return fmt.Errorf("Error creating kubernetes client: %w", err)
+	}
+
+	for _, cronEntry := range allCronEntries {
+		labelSelector := []string{
+			fmt.Sprintf("app.kubernetes.io/part-of=%s", appName),
+			fmt.Sprintf("dokku.com/cron-id=%s", cronEntry.ID),
+		}
+
+		if cronEntry.Maintenance {
+			err = clientset.SuspendCronJobs(ctx, SuspendCronJobsInput{
+				Namespace:     namespace,
+				LabelSelector: strings.Join(labelSelector, ","),
+			})
+			if err != nil {
+				return fmt.Errorf("Error suspending cron jobs: %w", err)
+			}
+		} else {
+			err = clientset.ResumeCronJobs(ctx, ResumeCronJobsInput{
+				Namespace:     namespace,
+				LabelSelector: strings.Join(labelSelector, ","),
+			})
+			if err != nil {
+				return fmt.Errorf("Error resuming cron jobs: %w", err)
+			}
+		}
+	}
+
+	return nil
+}
+
 // TriggerSchedulerDeploy deploys an image tag for a given application
 func TriggerSchedulerDeploy(scheduler string, appName string, imageTag string) error {
 	if scheduler != "k3s" {